Doburoku Sakaki (酒奇 溝六, Sakaki Doburoku) first appears during the Beach football match in the United States. He was a coach to Hiruma, Musashi, and Kurita, and taught them how to play American football.

Personality

Doburoku loves drinking sake; he has many different gourds, all of which look the same, but each contains a different kind of alcoholic beverage. His affinity for sake is also demonstrated by his quick revival when he is presented with more sake during the Deimon-Poseidon game; delusional, naked, and weak from his worldwide search for Komusubi, Doburoku wakes up and looks completed normal when Komusubi's dad brought the team sake.

He later ran off to the United States since he owed some loan sharks two million yen after gambling. He intended to look for talented people in America to play American football, but got into Beach football instead, training a team called Too Tattoos, who became better after undergoing his strict training regimens. After Hiruma gambles in Las Vegas, and pays off Doburoku's debts, he becomes the Deimon Devil Bat's coach and personal trainer.

He and Ojo's trainer and coach, Gunpei Shoji, were teammates at Sengoku University's American football team, and were known as "The Twin Japanese Blades", where he played as a tight end. Back then, the both of them participated in the Death March, with Shoji being on the defense line and Doburoku specializing in offense; Doburoku's philosophy, which was maybe passed on to Hiruma, was that the offense was the most important. However, after their other teammates gave up during the last 200 or so kilometers of the Death March, Doburoku overexerted himself in pushing the truck, resulting in an unrecoverable injury on his right knee.

Fearing that the Devil Bats might also ruin their potential athletic careers, he did not want the Devil Bats to undergo the Death March. However, he was quite amazed in their determination to do so and also for them being the only team to complete the Death March.

Despite being a good coach, he would sometimes rely on Hiruma for advice and final decisions. In the last quarter of the semifinal match between Ojo and Deimon, his philosophy of the ultimate offense clashes with Shoji's philosophy of the ultimate defense. When Shoji comments that Doburoku has raised a good team, the Devil Bats' trainer denies this, stating that the team had grown all on their own and that he is only in the way.

Doburoku has commented that he has never washed his clothes and has worn the same clothes for three years. Also, when he returned to Japan, he started work as the school's janitor, however, his salary went into Hiruma's account, where it will be used for maintenance and improvisations for the team.

Doburoku still tends to gamble as he wagers a million yen on Deimon's victory over the Nagas with the odds of 170 to 1. Though he becomes a millionaire after their win, he is once again put into debt when he bets his winnings on the Taiyo Sphinx to win against the Hakushū Dinosaurs, where the Sphinx are forced to forfeit during half-time.